Do you understand apparent wind?

this is just a simple poll to ask if you feel you understand the theory and practice of utilizing apparent wind in your sailing.

It ain't real hard.

If you're stopped, the wind direction is "true".

If you're moving, the wind direction is a combination of your forward motion and the "true" wind direction - the apparent wind.

ie. If the true wind is ZERO and you move straight forward, the apparent wind will be straight on your nose. Your motion through the air creates an "apparent" wind.

ie. If true wind is at 45 degrees and you start moving straight forward... the apparent wind angle is drawn more towards the nose.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

so i posed this question (slightly differently) on the beachcats site and had very different results...


1. Do you understand the principals of apparent wind?
13 yes 1 no


2. Do you feel you know how to utilize apparent wind in your sailing?
4 yes 6 no and 2 somewhats...

http://www.thebeachcats.com/module-foru ... l#pid16596

Let me ask you a question Andrew...
Do you use your tell tails while you sail? Meaning do you adjust the sail to consistently keep both the inner and outer tell tails at all locations flying straight back? If you do, then you are "utilizing" the apparent wind.

_________________
1992 Hobie Cat 18 #16943
Hobie Fleet 198, Rapid City, SD

With zero wind and current we had apparent wind from the rear in San Francisco bay once. It was a race in the morning and the sea breeze had not kicked in yet. Current was running probably 4 knots away from the windward mark. What wind we had died completely and the whole fleet started going backwards with the current. We thought the next wind would be the sea breeze and would be stronger than what we had to start with. We were able to set the spinnaker just from the apparent wind provided by the current. The rest of the fleet went backwards faster than we did and we soon had a pretty good lead, the sea breeze did come in. and we quickly dropped the chute and headed back upwind again. Unfortunately, the Committee decided to cancel that race because of unfair conditions.

This is exactly right. Every sailor, from the guy stepping onto a 5 knot mono-slug for the first time, to the guys going over 50kts "utilize" the apparent wind. Every time you look up at your wind vane, it is telling you the apparent wind direction, and this is what we all steer and trim our sails to. There really is no mystery as far as how to interpret and use the apparent wind- just look at your wind vane and telltales.

As far as maximizing the effects of the apparent wind, that might be a little trickier, but most cat sailors have a pretty good idea of how to take advantage of its effects to some extent. This is a simple as knowing that it's faster to tack downwind on a cat rather then sail dead downwind. Or the ability to "heat the boat up" by heading up slightly and then bearing off when doing the wild-thing downwind. But even that has more to do with the sailors' boat handling skills than some secret knowledge about apparent wind.

sm